The best way to practice problem solving is through chess. Below are some chess education videos:
Chess Introduction Video
Chess Intro & Interesting game
Game of the Century Byrne v Fischer
Combination Solutions
Bronstein Game & Combinations
Chess Combinations
More Combinations
Bronstein Faulkbeer Counter Gambit Game
Chess Combinations
King & Pawn Endings
Chess Combinations Continued
Chess Combinations ( more advanced problems )
Chess Combinations Complicated Problems
Rook endings: Fundamentals
Chess Endings review & Combination puzzles
Chess Summary
Queen & Pawn endings